Typically, gas turbine engines include a compressor for compressing air, a combustor for mixing the compressed air with fuel and igniting the mixture, and a turbine blade assembly for producing power. The compressor and turbine assemblies are formed of blades attached to a rotor interspersed with stationary stator vanes. The compressor and turbine assemblies include blades extending radially outward therefrom that are cooled with internal cooling systems and are collected into rows. Vanes extend radially inward and are collected into rows that are positioned between the rows of compressor and turbine assemblies. The stationary vane assemblies include seal arrangements with the rotor.
During operation, a seal holder attached to a stator vane tends to move upstream due to the pressure load acting in an upstream direction. The pressure load acts upstream because of a pressure difference between leading and trailing edges of the stator vane. During turbine engine operation as the compressor diaphragm outer hook wears, the upstream gap between the stator vane and the upstream rotor disk gradually reduces over time. As the stator vane moves toward the rotor disk, the gap reduces in size, and the seal holder will contact the rotor disk, which results in damage of rotor disk, the seal holder, and domestic damage of the compressor.
A wear pin has been used to determine the rate of closure of the gap between the stator vane and the rotor disk. The closure rate has been used to predict when the seal holder will hit the rotor disk. Such prediction has been used to schedule proper maintenance. The wear pin is usually formed from a plastic with low shear strength so that the wear pin wears without damaging the rotor disk upon which the wear pin contacts. The wear pin typically includes a threaded base and is screwed into place. The plastic wear pin often becomes brittle and breaks apart due to the compressor heat. As such, the wear pin becomes ineffective at predicting the gap closure rate. Thus, a need exists for a more robust system for determining compressor diaphragm outer hook wear.